Leisure activities have been emphasized as an important predictor of well-being. However, little research has examined the effects of leisure activity enactment on well-being over time. Moreover, it is unknown which activities are most beneficial for whom. We integrate diverse theoretical accounts of person–environment relations and propose a generic Personality–Activity–Well-Being (PAW) framework, which highlights different relations between personality traits, activities, and well-being. To investigate these relations, we used 11 annual waves from the Longitudinal Internet Studies for the Social Sciences (LISS) panel (total N = 12,703 participants, N = 59,108 assessments), which included measures of the Big Five personality traits, 15 different leisure activities, and affective well-being and life satisfaction. Our preregistered multilevel models revealed three sets of findings. First, we observed on average small expected between-person associations between leisure activities and well-being (e.g., higher average levels of holidays, evening socializing, talking to close others, exercise, and cultural activities were associated with higher well-being). Annual within-person fluctuations in several leisure activities also predicted well-being in expected ways, but effect sizes were very small and varied strongly across participants. Second, personality traits were related to leisure activities in hypothesized ways, yielding on average small but also some moderate and large correlations. Third, Personality Trait × Leisure Activity interactions were only evident on the between-person level, very small in size, and in the opposite direction of our expectations. Personality traits did not moderate well-being benefits from leisure within persons. We discuss the implications of our findings and sketch an agenda for future work.